A causal connector indicates that the source symbol is the cause or the origin of the target symbol. Causal connectors are the main operators in actors, wherein the modal response on the right is triggered by the context on the left.

A special kind of data that has been explicitly created by a user. Unlike other kinds of data, User Input often has a tautological association with context (e.g. A user has the goal of opening a file, because they have explicitly said they want to open the file), so as a result it is differentiated from general data.